Originally Posted by
gums
Salute!
Yeah, Buster, many of we colonists liked the Pratt motors as they were "robust". OTOH, the GE and Rolls motors were very high performance and lighter ( more thrust per pound). So I had a thousand hours in the Allison /Rolls fan in the A-7D with no problems, Great fuel consumption and so forth.
Best example of the fan bypass in the TF-41/Spey motor was ingestion of a flock of seagulls at Myrtle Beach. Motor coughed, belched and lost power. Pilot turned back and landed opposite rwy to show us the roasted birds!! Some were impaled on the bomb racks, but a few were lodged in the bypass duct. Suckers were toasty!
Gums recalls....
Yea Gums, back in the day the saying (at least on the commercial side) was that Pratt engines surged easily, and could happily surge all day long without doing any real damage. GE engines hardly ever surged, but if it did it was a light bulb - you removed and threw it away and installed a new one.
However, around 1990 that sort of changed - the new Pratt engines still surged on a regular basis, but now the surge might well break them, while GE engines still seldom surged, but if they did it usually didn't hurt them. It took until the early 2000's for Pratt to come out with a fix for the surge problems with the PW4000 - and it involved a
complete redesign of the HP compressor (and a very expensive mandatory retrofit to a fleet of several thousand engines).